Portable computers

ABSTRACT

A portable computer hand held cellular telephone arranged to rest comfortably in the hand has a small display screen. Accelerometers capable of detecting movement of the pen cellular telephone with respect to gravity provide input to a microcontroller which selects a response from a number of viewing modes. The pen cellular telephone may be held in either hand and the output message to the screen will be oriented according to the location of the pen cellular telephone. Full personal digital assistance functionality may be incorporated in a relatively small plastics casing and functions, such as calendar, contracts contacts and the like may be incorporated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional broadening reissue application ofbroadening reissue application Ser. No. 13/188,239, filed Jul. 21, 2011,which in turn is a divisional broadening reissue application of Ser. No.11/907,832, filed Oct. 17, 2007, now U.S. Pat. No. Re. 42,738; which inturn is a broadening reissue application of Ser. No. 09/171,921, nowU.S. Pat. No. 6,956,564, issued Oct. 18, 2005; which is the 35 USC 371National Stage Entry of International patent application serial numberPCT/GB98/03016, filed Oct. 8, 1998, claiming priority of GB9722766.4,filed Oct. 28, 1997, the entire disclosures of which are hereinincorporated by reference in their entireties; and is related to thefollowing reissue applications: Ser. No. 12/255,557, filed Oct. 21,2008; Ser. No. 12/268,254, filed Nov. 10, 2008, now U.S. Pat. Re.44,103; Ser. No. 12/268,336, filed Nov. 10, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to portable computers and moreparticularly but not exclusively to hand-held computers of the kindsometimes referred to as personal digital assistants.

2. Related Art

A personal digital assistant includes data files defining such items asan electronic diary, address book and other applications such as wordprocessing software, calculators and the like. As more powerful memoriesand processors have been developed in smaller packages it has becomepossible to provide quite powerful computers in relatively smallportable eases. However, the limitation of miniaturisation occurs when aviewing screen and keyboard are needed for data input and read out.Thus, so called palm top personal computers (PPC) are usually of theorder of 15 cm by 7 cm in order to provide a readable screen and ausable keyboard. Such palm top computers are known, for example PsionCorporation have produced a Psion Series 5 (trade mark) PPC having an 8megabyte RAM and processor while Hewlett Packard similarly produce PPCsas e.g. the HP320LX (trade mark). The capabilities of such PPCs may beenhanced by incorporating so called flash cards enabling the expansionof the RAM by up to 10 megabytes or more while PCMCIA cards may beprovided to enable connection of the PPC to telephone networks by way ofcellular phones or telephony sockets for communication with othercomputers and the so called Internet and Intranets.

Most PPCs incorporate it docking arrangement to enable them to beconnected with a desktop computer or other main frame for the purposesof synchronisation of data files and the like.

However, generally speaking PPCs are not robust and are prone to damagemainly because of the clam shell design requiring a hinge that opens toreveal the incorporated keyboard and screen. Thus PPCs are more usuallyused on a desk top or table or may be held in one hand while typing withthe other.

SUMMARY OF THE INVENTION

According to the present invention there is provided a portable computerincluding movement detection means responsive to movement of thecomputer to produce an electrical output signal representative of suchmovement, processing means responsive to the output of said positiondetection means to determine detected movement data defining a user'sintention, the processing means using said data to provide a moderesponse selected from a multiplicity of stored possible modes.

Preferably the movement detection means includes at least oneacceleration or tilt detection means responsive to movement of thecomputer to produce the output electrical signal. There may be aplurality of acceleration detection means each producing a respectiveelectrical output signal representative of movement components inrespective directions, the detectors generally being mounted to detect Xand Y movement components at a ninety degree angle.

The processing means may include a data input mode in which detectedmovement data is used to generate alphanumeric or graphical data. Thealphanumeric or graphical data may be stored in data storage of theportable computer or may be output by transmitting means to receivingmeans connected to another processing device.

The processing means may include a screen output mode in which detectedmovement data is used to modify output to display means of the computerwhereby scrolling of displayed information is effected. In the screenoutput mode the processing means may be responsive to relative lateraltilting movement to cause the display of information stored as to one orother side of currently displayed information. Relative rolling movementmay cause the display of information stored as above or below thecurrently displayed information.

In the screen output mode the processing means may be responsive todetected movement data to determine a most likely orientation of thecomputer display means with respect to a user's eye line whereby thesignals output to the display means may cause inversion of the displayedinformation such that the computer may be held and used in either hand.

The computer may include proximity detection means arranged to providesignals indicative of the proximity of the display screen to a user'sview, the processing means being responsive to changes in the relativeproximity to increase or decrease density of displayed information.

In a further development, security data derived from movement of thecomputer defining an authorised user's password is stored, theprocessing means being locked in a secure mode until detected movementdata corresponding to the security data is received.

The computer may include a sound input device, the processing meanshaving a second data input mode in which alphanumeric data is derivedfrom input speech signals. A sound output device may also be included topermit the output of speech derived from stored data. Alternatively thesound input and output devices may be combined with a radio transceiverwhereby cellular or other radio telephony networks may be used.

The computer may be housed in a casing shaped to facilitate a userholding the computer as if holding a writing stylus. The casing ispreferably of substantially radiused triangular cross section along asubstantial portion of its length and may include a flattened sectionincorporating a display screen. The casing may include angular shapingbetween a forward holding area and a rearward screen area the shapingbeing such as to provide a natural viewing angle of an incorporateddisplay screen while the casing is held as a writing stylus. The shapingmay also be such as to facilitate support of the rearward screen area bythe dorsal aspect of a user's hand between the root of the thumb andindex finger and the wrist.

BRIEF DESCRIPTION OF THE DRAWINGS

A portable computer in accordance with the invention will now bedescribed by way of example only with reference to the accompanyingdrawings of which:

FIG. 1 shows a plan view of the computer;

FIG. 2 shows a side view-of the computer of FIG. 1;

FIG. 3 is a block schematic diagram of the circuits of the computer ofFIG. 1;

FIGS. 4a and 4b provide a circuit diagram showing details of thecircuitry described with respect to FIG. 3;

FIG. 5 is a circuit diagram of a docking station to enable the computerof FIG. 1 to be connected to a desktop or other device;

FIGS. 6 to 9 are flow charts showing some of the programs incorporatedin the microprocessor of FIG. 4;

FIGS. 10 to 13 are graphical representations of the outputs of theaccelerometers of FIG. 4 as analysed by the microprocessor;

FIGS. 14a and 14b provide a graphical comparison of the representationsof the outputs of the accelerometers as shown in FIGS. 10 to 13;

FIG. 15 is a schematic diagram of a power saving arrangement of theportable computer of FIG. 1;

FIG. 16 is a schematic diagram of a voice input arrangement of theportable computer of FIG. 1;

FIG. 17 shows mounting positions of the accelerometers of FIG. 4 withrespect to each other;

FIG. 18 is a table showing a program response to movement of theaccelerometers of FIG. 16 in a particular mode of operation; and

FIG. 19 is a schematic diagram of a part of a scroll detector of theportable computer of FIG. 1

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring to FIGS. 1 and 2, the hand-held computer of the presentinvention has a case 1 of a moulded plastics material having atriangular barrel cross section towards the forward end, that is towardsthe point, with radiused sides providing a diameter of approximately 15mm. The case is shaped to have a curve so that when the forward part ofthe barrel of the casing is held as a writing stylus using the thumb,index finger and second finger of the user, the screen area A—A restscomfortably on the dorsal area at the back of the hand between the rootof the thumb and index finger of the hand and the user's wrist. Thisprovides some additional support to allow the entire computer to beoperated using one hand only. After assembly the case is sealed using anO-ring seal much in the manner of sealing watch parts. Coating thecasing with wax polythene completes the sealing of the unit so that toall intents and purposes the case is waterproofed.

The casing is weighted at one end (for example by including arechargeable battery 2) at the forward end so that if the item isdropped on to a surface it tends to fall in a specified manner such thatthe tip which may include some impact protection, for example by beingrubber cased, prevents any significant damage to internal components.The weighting also assists balancing of the unit in a user's hand.

The case may incorporate a hook 3 for attachment of a strap or key ring(not shown) and may have a pocket clip 4. The hook is preferablyrecessed within the casing.

Externally mounted a small liquid crystal diode screen which may be ofthe kind manufactured by Batron and supplied under type numberBT42003STYC is included. To either side of the LCD 5 touch or pressuresensitive switches 6 to 13 are provided. These switches may be softprogrammed to provide functions as hereinafter described. A touch scrollstrip 14 (hereinafter described) is provided in front of the screen 5and the system includes a pyroelectric detector 15 used in determiningthe proximity of the computer to a user's eye.

Audio input and output devices are also provided together with analerting device. For example, a microphone 16, annunciator 17 andspeaker 18 may be included. Finger switches 19a, 19b, 20 are providedforward of the annunciator 17 and again may be soft programmed forfunctionality. Also visible are gold docking pins 21 used for connectingthe hand-held computer for recharging of the battery 2 and transfer ofdata by way of a docking device to other computers, for example deskmounted personal computers.

As an alternative means of transferring data from the computer of theinvention to another processing device or to enable the computer of theinvention to be used as an input device for a PC, an infraredtransceiver 22a, 22b is mounted towards the front of the casing 1.

Also included is a light emitting diode 23 which may be of the kindhaving three or more colours. Individual colours allow for a smallamount of illumination or may be used to provide indication or alarmfunctions. Alternatively, a single coloured red light emitting diodepart TLSH180P from Toshiba may be used. This ultrabright LED aids humannight sight viewing and whilst only being of low power may in a darkenvironment assist the user.

Turning now to FIG. 3, a block schematic diagram of the component partsof the computer is shown. It will be noted that the display 5 receivesinputs from a microcontroller 30 which may be of the type supplied byMicrochip under the reference PIC16C74. The PIC16C74 includes on boardread only memory (ROM) but in a preferred embodiment an ARM processorwith a larger memory is used. Also mounted within the casing 1 are twoaccelerometers 31, 32 which may be of the kind known as ADXL05 fromAnalog Devices Limited and which are buffered by operational amplifiers,for example National Semiconductor type LPC662. The keys 6 to 13 and 18to 20 are here represented as a keypad 33. Some of the keys may be usedto control a speech recorder 34 which is also used as an interfacebetween the microcontroller 30, and microphone 16 and the speaker 18. Aradio transmitter 35, which may be a radio transceiver, is alsoincorporated.

One function of the radio transmitter may be to allow use of thehand-held computer of the invention as an input device for a deskmounted or other PC 40 having corresponding receiver 36 and anappropriate converter without physical interconnection. Other functionsof the transceivers 35, 36 may be apparent from the descriptionhereinafter.

Referring now to FIGS. 4a, 4b the microcontroller 30 is connected to thedisplay 5 using standard control inputs of the display to provide avisual output of the result of program activities requested by the user.It will be noted that the accelerometers 31 and 32 have associatedbuffer circuits which each include an operational amplifier to bufferthe input to the microcontroller. The operational amplifiers 41 may betype LFC662 from National semiconductor.

Power to the accelerometers 31 is by way of a transistor TR2 so that ifthe microcontroller 30 determines that no movement of the computer isoccurring or that the present program does not require use of theaccelerometers 31 and 32, output RB1 may be set to stop current beingdrawn to minimise battery usage. The microcontroller may allow periodicsampling during dormant periods so that if the computer is picked up thesensors may again be activated.

An EEPROM integrated circuit chip type X24F064 8 Kbyte from Xicorproviding 8 Kbytes of memory is also provided accessible from themicrocontroller 30 in known manner. Switches S1 to S8 (keys 33 in FIG.3) are wired to respective inputs of the microcontroller 30.

Note that TR1 controls power input to the back lighting circuitry of theLCD display 5. Again, the microcontroller 30 will normally bias TR1 offwhen the computer is dormant and will maintain TR1 biased off unlessback lighting is requested by operation of one of the keys of thekeyboard 33.

For the avoidance of doubt it is here noted that the microcontroller 30includes a program which uses position outputs from the accelerometers31, 32 to determine from the orientation of the computer whether thehand-held computer is in the left hand or right hand of the user. It ishere noted that accelerometer output may depend upon the tilt angle ofthe included accelerometers to the earth's gravitational field. The keysS1 to S8 are then swapped over in soft programming mode such thatfunctionality is determined by the apparent top of the display 5 to theuser in its current position. Similarly, determination of orientation ofalphanumeric or other display information on the screen 5 will bedetermined from the orientation of the computer itself. Thus, dataoutput to the screen from the controller 30 arranged to provide anappropriately oriented display.

The speech recorder 34 is implemented using Sequoia technology soundrecording integrated circuit type ISD2560. The Sequoia technology chipis capable of recording 60 seconds of speech message in digital form andis connected so that the microphone 16 can be used to provide an input.The three switches SW1, SW2 and SW3 may correspond to the fingertipswitches 18 to 20 of FIG. 1 or may be selected in software from keys 6to 13.

In speech recording mode SW1 provides a start and pause control functionfor the user, SW2 is a stop or reset function while SW3 switches betweenthe record and play modes.

Short messages are played back by way of the loud speaker 18. Ascurrently implemented the microphone 16 is a Maplin type QY628, thespeaker is from Hosiden type HDR9941. “Speech notes” recorded by thismethod may be down loaded to a PC for sorting and categorising.

Turning briefly to FIG. 5, the hand-held computer of FIG. 1 can beinserted in a corresponding docking port shaped to align the contact 21with T5 to T7 of FIG. 5. The contact T5 and T8 provide serial receiveand transmit paths for synchronising databases between a PC and theportable computer and also provide battery charging. Contact T7 providesan earth contact. Speech samples and other data may be up loaded from aPC to the portable computer.

A Maxim integrated circuit 42, which may be type MAX232IC, convertsRS232 level serial output and input required by current PCs to thevoltage level required by the microcontroller 30 of FIG. 4. Note alsothe ability to receive radio input by way of an antenna connected to theradio receiver chip type AMHRR3-418.

Having discussed the hardware of the portable computer of the inventionwe shall now consider various uses to which the writing stylus input,voice input and screen may be used. Exemplary flow charts for someaspects of the use of the portable computer are attached. Whilefunctions are individually discussed in respect of the flow charts ofFIGS. 6 to 9, it will be appreciated that combinations of programs maybe used in the implementation of features described hereinafter.

Turning now to FIG. 6, the tilt sensor software uses inputs from theaccelerometers 31, 32 which, as shown in FIG. 17 to which reference isadditionally made, are mounted with their respective sensitive axes atright angles to each other. As will have been seen from FIG. 4, theoutput from each accelerometer is filtered by a resistor capacitancenetwork to remote high frequency noise for example, and the outputs arethen read by an analogue to digital converter included within themicrocontroller 30. Thus, referring to FIG. 6, for special sensing themicrocontroller 30, display 5 and analogue to digital conversioncircuits are initialised at 100 and the interrupts and port pins of themicrocontroller 30 are reset or cleared at 105. The output of theaccelerometers 31, 32 is read from respective analogue input pins AN0and AN1 of the microcontroller 30 and an index to a look up table iscalculated at step 110 using the formula I=a+(b1×16). In this case a iscalibration constant and b1 is the digitised output of the accelerometer31. This allows for a look up table allowing a16 by 16 matrix of left toright position to be determined. For vertical tilt position the formulaI=a+(b2×16) where b2 is the output of the accelerometer 32 may be usedto address a further matrix to determine the relative up/down position.By applying one or more of the indices to the look p table, it ispossible to select one of n screen positions or to determine the amountof movement since the last reading at step 115. The system then waitsfor 10 ms as indicated at step 120 before repeating the reading of theaccelerometer output.

The program allows for the screen 5 to be scrolled in accordance withthe user's requirements. The mounting of these sensors, as shown in FIG.17, allows posiitonal movement such as up, down, left and right toresolved to fractions of a degree.

Using software the microcontroller 30 may use the output from theaccelerometers 31, 32 to determine a user's requirement for a differentview to be displayed on the screen 5. Thus a virtual hinge is createdsuch that if the user moves the stylus whilst it is in viewing positionthe screen information may be changed to respond to a natural reactionfor looking up or down or to the left or right. Thus, as shown in FIG.18 in a simplified arrangement, if the display on the screen at any timeis designated as current page (CP) then tilting the stylus towards theleft will cause the display of a page stored as to the right of CP (CR).The page which was formerly CR (as represented by data held within thestorage of the microcontroller 30 or an associated data store) is nowCP. Tilting the stylus to the right will cause a page of information(CL) to the left of CP to be displayed. For the avoidance of doubt theterm page is used here as for a screen for information. Thus the actionof tilting the stylus to the left or right is analogous to the naturalinclination to look through a window towards the right or left to obtainadditional information from a scene.

Similarly, if the stylus is turned towards the user information storedat UC will be displayed and tilting the stylus away results in theinformation DC being displayed. It will be appreciated that combiningtilt angles may result in the display of information up and to the left(UL), up and to the right (UR), down and to the left (DL) and down andto the right (DR). This simplified description of a multiple line screenmoving as if a jump is occurring should be considered as allowing singleline scrolling in which CP defines the top line of the screen, DC theline below and further lines to the limit of screen viewability alsobeing displayed with CP such that single line scroll movement or smoothscrolling appears to occur. Finer scrolling modes such as single pixelmovements are also possible. The user may select the rate of responseusing keys 6 to 13 or fingertip switches 18 to 20. It should also benoted that the tilt sensor arrangement 31, 32 allows the microcontroller30 to determine the most likely viewing angle and to adjust pixelmapping to the screen accordingly so that if a user holds the stylus inthe left hand the display is inverted to that shown in FIG. 1 so thatthe bottom right corner, as viewed by a right handed user, becomes thetop left corner as viewed by a left handed user. It should be noted thatthe microcontroller does not require an input from the user to determinewhether the stylus is being held in the left or right hand and, if auser changes hands during the course of viewing the screen output willbe inverted accordingly.

It is also possible, particularly if pictorial rather than alphanumericdisplay is required, for the screen to enter a “portrait” mode if thestylus is held vertically. In this case the orientation will beappropriate to the stylus being held with its tip above or below thewaist of the stylus.

To prevent scrolling or orientation change the user may use a soft key 6to 13 or fingertip switch 18 to 20 to lock and unlock display movement.

Further, while as described with reference to FIG. 3, the display screenis a Batron, in a preferred embodiment a Kopin Cyberdisplay 320 having ¼VGA colour resolution may be used. Using the Kopin display and theassociated monocular viewing lens mounted end on to the body allowsclear viewing of some 15 lines of normal text. The Kopin Monocular lensis approximately 20 mm by 18 mm which gives an acceptable size to a penbody incorporating movement sensing means as herein described.

In a still further development the pyroelectric detector (Murata typeIRA- E700STO) 15 may be used to detect the presence of the user and theproximity of the user to the viewing screen 5. Using the Kopin ¼ VGAdisplay it is possible to decrease the size of character displayed. Thusthe microcontroller 30 uses the output of the pyroelectric detector 15to determine how close to a user's eye the stylus is held and may adjustthe size of print so that more characters are fitted on the screen 5. Inthis way large areas of text may be read by holding the screen close tothe user's eye. A further use of the pyroelectric detector for powersaving purposes it discussed hereinafter. As has been mentioneddetection of the position of the screen with respect to the user's leftor right side is possible.

Referring to FIG. 8, clearing of interrupt and set port pins andinitialisation as previously mentioned with regard to FIG. 6 is carriedout. One of the accelerometers, for example the accelerometer 31, isread at step 200 and its value compared with a predetermined value m.Values greater than m indicate that the display is most likely in theuser's left hand so that as indicated at 215 inverted characters aredisplayed on the screen 5. If the value read from accelerometer 31 isless than m then it may be assumed that the stylus is in the user'sright hand and normal ROM LCD characters are displayed. As indicated at220, a check may be carried every 10 ms to determine the whereabouts forthe screen.

It is envisaged that input to the computer system either for use as aPDA or for word processing purposes, will be carried out either by handwriting recognition (HR) or by voice input using the microphone 16.Handwriting recognition does not require the user to write on a surface,although some users may find this a preferable method of operation, butrequires the user merely to move the stylus (that is the whole computer)as if writing letters and numbers. Katakana or Cyrillic texts may alsobe entered as may symbols.

Thus using one of the two accelerometers 31, 32 and referring to FIGS.10 to 14, the output of one of the accelerometers 31, 32 is read at asimple rate of 100 times per second. The received data is stored in arandom access memory (RAM) buffer as a set of acceleration valuesagainst unit time. Using a software process of autocorrelation themicrocontroller 30 may determine the character entered. Thus, referringto the Figures, FIG. 10 shows three entries of the letter C, FIGS. 11shows three entries of letter B, FIG. 123 entries of letter F and FIG.13 three entries of letter H for exemplary purposes only. Feedback tothe user either on the display or by character speech output or simplyby an acoustic beep indication may be used to note acceptance of acharacter. The validity indication may be user selectable.

It will be noted from FIG. 14 that a single accelerometer output isdistinct for each of the input characters and therefore themicrocontroller can determine the entry made. The entry may be of textwhich can be reflected to the viewing screen 5 or maybe instructionscouched in appropriate terms such as “get Monday diary”. Once the diaryhas been recovered from the store the appropriate entries may bedisplayed on the screen 5 with appropriate soft key indications for thekeys 6 to 13.

Note that predefined user gestures such as drawing an “envelope” torequest e-mail mode or a table for diary mode, for example, may be used.The instructions may be user selectable or teachable so that oninitialisation the user draws and selects the mode. Subsequently drawingthe same symbol will cause the microcontroller 30 to enter theappropriate selected mode.

Again sensing may be used to move around the displayed area (asdiscussed with reference to FIG. 6 and FIG. 18) or the touch stripcontroller 14 may be used in combination with the keys 6 to 13 to selectappropriate areas.

Entry of information to the diary may also be by handwriting input. Itis convenient here to consider the construction of the touch strip 14which as shown in FIG. 19 comprises a 0.4 mm printed board having asurface area of approximately 20 mm by 5 m with horizontal strips in the5 mm dimension as indicated as 47 to 50 for FIG. 19 which shown a partof the strip 14. The strip 14 thus replaces the rotational elements ofpotentiometer so that hermetic sealing of the casing may be complete anda control which is resistant to wear as provided. The strips 47 to 50etc, are interfaced to the microcontroller 30 so that as a finger ismoved across the strip direction of movement and speed of movement maybe determined. The information may be used in the same way as a rotarypotentiometer.

It will be appreciated that incorporating a second strip at right anglesto the strip 14 would allow full functionality of (eg) a computer mouseto be simulated.

Thus as shown in FIG. 19, if a user moves a finger such that, forexample, the presence of the finger bridging 48, 49 and 50 subsequent tothe presence of a finger bridging 47 to 50 indicates that the user wouldwish to rotate a potentiometer in a counter-clockwise direction.Similarly, detection of a finger bridging 47 and 48 subsequent to therehaving been no previous bridge indicates rotation in a clockwisedirection.

It will be appreciated, however, that if the tilt detection mechanismhereinbefore described indicates that the device is in the left handrather than the right hand the functionality of bridging and unbridgingis reversed accordingly.

Entry of data files, for example the composition of letters or reportscan be carried out using either the write sensing arrangement,hereinbefore described, to determine input alphanumeric which may bestored for subsequent transmission to a printer or for transfer as datafiles to a PC for example. Data entered and converted into appropriatestored information may be displayed on the display screen if required.

Cursor movement around the display screen to select a position to whichinformation is to be placed may be by use of either the potentiometerarrangement described with reference to FIG. 19 or by use of the tiltsensing mechanism hereinbefore described in combination with one of thesoft keys to indicate that an insert or delete position is beingselected.

In an alternative method of operation and referring to FIG. 7a andinitially to FIG. 7b, use of the stylus of FIG. 1 as a non-connectedinput device for a PC allows all of the functions of the hand heldcomputer to be duplicated. For example, where alphanumeric data is inputin the manner previously described with reference to FIGS. 10 to 14 amore powerful PC may be able to effect autocorrelation much more rapidlythan the microcontroller 30 of the device itself. In this case,referring specifically to FIG. 7b, once the initialisation process hasbeen completed at 100, one or both of the accelerometers may be read at705 at 10 ms intervals as indicated at step 710 and the voltage data istransferred to the serial port for transmission by the wireless link orby use of infrared transmission.

A corresponding program in the PC itself will read from radio receiver36 and the receive port the data defining the voltage from one, or boththe accelerometers. Autocorrelation will be carried out on the readingto generate appropriate characters at step 725, the characters beingdisplayed on the PC screen at step 730 and possibly being transmittedback to the hand-held PC.

In an alternative implementation autocorrelation may be carried outwithin the microcontroller 30 and data defining input charactersthemselves be transmitted to the PC.

Note that the transmission of comma separated variables (CSV) formatASCH is transmitted at 418 MHz using an amplitude modulated radiotransmitter from RF Solutions of Lewes East Sussex UK. In the PC CMOSvoltage levels converted by the RS232 conversion unit can be used toprovide raw data to the PC. Windows 3.1 terminal software is capable ofreading CSV data and spreadsheet can read and plot data graphically.

In a still further use of the accelerometer 31, 32 arrangement passwordprotection of the hand-held computer may be provided. Thus, once trainedto a user's signature, for example, a stored waveform corresponding toaccelerometer voltage outputs read at 10 ms intervals can be used. Thusthe user does not require to remember any special passwords and crackingof the signature code is extremely difficult since, for example forginga signature will result in a different acceleration pattern to that ofthe natural signature writer.

Thus it may be possible to use a hand-held computer of this nature toprovide transmission of security information for, for example,electronic point of sale authorisations, access restriction and thelike.

A still further use of the transmission and reception capability allowsa local area paging system to be developed. Thus if several users workin reasonable proximity to each other it is possible to transmit amessage directly from one hand-held computer to another such that, forexample, telephone messages taken by one person in an office and filescreated may be transmitted using a digital serial identity to anotherspecified hand-held computer unit.

Turning to FIG. 16, in addition to the simple 60 second voice notestorage chip 34, the microphone 18 may also be connected by theamplifier and filter arrangements to provide voice input to themicrocontroller 30. Voice recognition software can thus be used toconvert the voice input to data, the keys or fingertip switches 18 to 20having appropriate use for pause, record, etc as hereinbefore describedwith reference to the spoken memorandum chip. Converted data can thus betransferred to the memory or displayed on screen or as hereinbeforedescribed with reference to using pen input for handwriting correlationby a PC serial data to the PC representing the voice input can beprovided. This is indicated at 39.

In an alternative method of working, the microcontroller causes storageof the speech input in the memory 38 without effecting conversion, theinformation being transmitted via the serial output port either in thedocking station or by the radio link to a PC which may use voicerecognition software to carry out the conversions. It may be preferableto use a PC to carry out the conversion rather than a microcontrollerincorporated in the pen since significant processing power may berequired. However, the inclusion of voice recognition software in themicrocontroller 30 is possible.

It will also be realised that a data store may be used to store receivedspeech signals. Thus several speech notes each time/date stamped may beheld for subsequent use. If a suitable store is included then the speechstorage chip, hereinbefore described, may be omitted from the stylus toallow additional memory chip space.

It will be noted that since the hand-held computer of the inventionincludes microphone, loudspeaker and function keys use of the device asa cellular telephone is also envisaged.

Where cellular phone functionality is included within the stylus orwhere the stylus is in contact with a PC for example by IRDA or radiotransmission, the use of the microphone input for substantial dictationpurposes is possible and also the use of substantially larger data filesthan could otherwise be stored locally.

Thus the input speech will be stored in a buffer by the microcontroller30 and periodically, when the buffer contains a substantial amount ofdata, a network connection to either network data storage means or to apredetermined PC is effected. Stored buffered data is then transferredto the remote location. Since the network connection is not permanentlyrequired the cost of transferring the data by this means is lesssignificant and periods of network signal weakness can be overcome.

Data buffered in this manner may be date and time stamped or, if thestylus incorporates GPS (global positioning systems) may be locationstamped also.

Data may similarly be recovered such that large text documents requiredby a user may have portions stored in the buffer for display andsequential recovery of other parts of the document from the remotelocation using telephony as required. Photographic data, for examplefrom a digital camera, may similarly be saved to the network by way ofthe buffered store.

The various functions above described enable the provision of a full PDAfunction including diary alarm and scheduling functions as well as datainput, file creation and storage. The user may select the mode ofoperation using either soft buttons or movement input and the use of theaccelerometers 31, 32 is determined from the mode selected by the user.Electronic mail and fax facilities may be incorporated in the PDAfunctions allowing reception or transmission of data via the unit. Thetransmission capability of the unit may be associated with a receiver ina printer for example or a printer incorporating a docking station maybe used to allow the printing of data from the PDA. Note that infraredtransmission may be used.

As will be appreciated one of the major problems with any hand-heldportable device is the use of rechargeable batteries which have alimited power life between charges. The hand-held computer of thepresent invention therefore incorporates a number of power savingfacilities arranged particularly to close down back lighting of thesmall LCD screen 5 if it is not appropriate. Thus if the accelerometersindicate that there is no current usage of the system then powering downof the detection circuitry and back lighting of the screen may occur.However, in a further use of the proximity detector 15, it is possibleto turn back lighting on and off in dependence upon whether the user islooking at information on the screen or not. Thus, referring to FIG. 15,the pyroelectric detector conversion detects presence of movement tomaintain back lighting. Pyroelectric detectors tend to detect presenceof a person by movement through a parallel beam of infrared such thatwhen movement is detected across a Fresnel lens an AC signal isgenerated.

Thus the pyroelectric system can be used to detect the presence of auser and in the absence of use power down of the back lighting at leastmay occur. Infrared sensors may similarly be used to detect the presenceor absence of body heat. Note the pyroelectric detector, as previouslydescribed, can be used to control the character zoom featurehereinbefore described. A suitable detector is a Murata type IRAE700STO.

In a further implementation of back lighting power down which isresponsive to the viewer's vision in addition to the viewer's presence.It is known that when a subject looks directly at a lens and a flashoccurs blood vessels at the rear of the eyes reflect back to the camera.It is thus possible to periodically flash a low level light and to sensered reflection using a photodiode sensor. Thus as shown at FIG. 15, themicrocontroller 30 periodically causes an LED 60 to pulse. At the sametime a photodiode 61 is monitored and, assuming presence of a user's eye62 reflecting light from the pulse, the LCD will remain back lit asindicated at 58. It is further noted that a custom-built solar cell (notshown), for example a Solarex available from Farnell Electronics, may beused to assist triple charging of the battery 2.

If a user is not looking directly at the screen at the time the LED 60is flashed there will be no reflection and the photodiode 61 will notactivate. The microcontroller may therefore power down the back light 58thus reducing the drain on the rechargeable battery 2.

Although the present invention has been described with reference to aparticular implementation using accelerometers other position detectionand location means may be used to implement movement detectionarrangements. While herein references made to alphanumeric data it willbe appreciated that katakana character and Cyrillic script inputs mayalso be detected using the acceleration method hereinbefore described.

Note when the hand-held computer is docked with a PC or is receivingdata by way of cellular or radio transmission it is possible to displayreceived information on the screen 5. Thus as indicated at FIG. 9 aninitialisation message is output to the screen 5 and an appropriatebuffer is cleared. As characters are received at the serial port theyare transferred to the microcontroller at 905 and checked for framevalidity at 910. Assuming that there is no error at 910 and that thereceived character is not a clear screen message as indicated at 915then a character is transferred to the LCD 5 for display at 920.

Further possible uses of the portable computer of the invention includestoring large numbers of speech modes which when down loaded to a PCwith the pen either in a docking station or by IRDA or radiotransmission are sorted. In this process the PC converts the each of thespeech notes to text and scans the text for frequently occurring words,for example “meeting” and then sorts the stored notes intosub-directories. Alternatively, notes may be sorted by date, subjectmatter or size as will occur with a normal windows file. Key controlwords such as “alarm” may result in the speech note being converted intoa timed alarm which may then be written back to the portable computer sothat at the appropriate time the portable computer either announces thealarm or a vibrate to alert the user, the alarm being displayed as atext message. It will be appreciated that if a sufficiently powerfulmicrocontroller is used in the pen then the speech to text conversionmay take place in the portable computer unit. A suitable vibrating motorfor use as a silent alarm can be obtained from Murata of Japan.Situating the annunciator towards the barrel of the pen near the tipimproves transmission.

The microcontroller may cause audio feedback of the current position ofthe stylus, for example by causing sounds of flicking pages when the penis tilted forward or back.

While most emphasis herein has been on the display of alphanumeric,Katakana or Cyrillic characters, graphic information may also be viewed.For example, a file holding pictures related to a person may includethree dimensional picture of that person's face. By revolving or tiltingthe computer the view may switch from a front view to a profile aspect.It will also be appreciated that an atlas may be stored in the datastore and maps may be rotated to align with the direction of travel forexample.

Additional functionality may be introduced to the hand-held computer byincluding a touch screen in front of the display screen such that astylus can be used to select text or to cause localised movement of acursor.

An autolocate function may be built into the microcontroller such thatif no movement, ie no change in tilt of either the enclosedaccelerometers occurs for a selectable period, probably 24 hours, theunit will sound an alarm at periodic intervals so that the user canlocate it.

Note that the tilt sensors included herein measure tilt with respect toearth's gravity by use of a small beam arrangement. Other positionsensors may be included. Global positioning By satellite is also apossible method of detecting a change in the position of the portablecomputer.

In a symbol counted mode it is possible for a user to flick the peneither as a tick or a cross, for example, in relation to a submitteddocument. The number of ticks or crosses may be counted and the resultaccumulated and transferred to data store or accumulated in aspreadsheet to which the user may input names, titles and the like. Theuse of other symbols in anticipated.

While as hereinbefore described the security signature is by use ofacceleration, a pressure detector may be incorporated into the end ofthe device to further increase security by measurement of the profile aswell as the two dimensional or three dimensional spatial sensor.

As has been mentioned hereinbefore, a number of keys, switches andbuttons are provided on the casing of the portable computer. In afurther implementation an on/off switch may be provided operated bypressure on the “nib-end”. Whilst such switch pressure is not used fordetecting Input text per se, it may be used to turn functions on andoff. This may be used in a normal writing mode, for example, touchingthe pen tip against a writing surface to turn on the accelerometerdetection functions. Releasing pressure on the tip then stops theaccelerometer signals being considered as potential input to be decoded.

Any of the other switches may be used in certain modes to turn on or offtext detection, for example, or to stop screen scrolling for example.

Calculator functions in the portable computer may be provided simply bywriting the numerals and appropriate mathematical symbols in the normalmanner. The tilt sensor software will determine the numerals andcharacters entered and perform an appropriate calculation for display onthe display screen.

A further function, for example for clock setting causes Display of ananalogue clock face on the display means 5. Time changes may be enteredby selecting an appropriate mode and moving the user's write. Tiltsensing is used to determine forward or backward adjustment of the timestored.

What is claimed is:
 1. A portable computer comprising: movementdetection means responsive to movement of the computer to produce anelectrical output signal representative of such movement, a storagemedium for storing data defining a multiplicity of displayable pageseach comprising of a plurality of lines; a display having acorresponding plurality of lines to enable one of the multiplicity ofpages to be displayed; and processing means responsive to the output ofsaid movement detection means to determine detected movement datadefining a user's intention; the processing means using said movementdata to provide a mode response selected from a multiplicity of storedpossible modes, at least some of which define selection for display of afurther one of the pages from the multiplicity of pages, the further oneof the pages being adjacent to a previously selected page beingcurrently displayed; wherein detected movement data is used to effectscrolling of displayed information such that portions of data definingalphanumeric or graphic information outside a currently displayed screenis selectable by the user, the scrolling of displayed informationeffectively displaying a part of an adjacent screen.
 2. A portablecomputer comprising: movement detection means responsive to movement ofthe computer to produce an electrical output signal representative ofsuch movement; a storage medium for storing data defining a multiplicityof displayable pages each comprising of a plurality of lines; a displayhaving a corresponding plurality of lines to enable one of themultiplicity of pages to be displayed; and processing means responsiveto the output of said movement detection means to determine detectedmovement data defining a user's intention; the processing means usingsaid movement data to provide a mode response selected from amultiplicity of stored possible modes, at least some of which defineselection for display of a further one of the pages from themultiplicity of pages, the further one of the pages being adjacent to apreviously selected page being currently displayed; in which a relativelateral tilting movement causes the display of information stored as toone or other side of currently displayed information.
 3. A portablecomputer comprising: movement detection means responsive to movement ofthe computer to produce an electrical output signal representative ofsuch movement; a storage medium for storing data defining a multiplicityof displayable pages each comprising of a plurality of lines; a displayhaving a corresponding plurality of lines to enable one of themultiplicity of pages to be displayed; and processing means responsiveto the output of said movement detection means to determine detectedmovement data defining a user's intention; the processing means usingsaid movement data to provide a mode response selected from amultiplicity of stored possible modes, at least some of which defineselection for display of a further one of the pages from themultiplicity of pages, the further one of the pages being adjacent to apreviously selected page being currently displayed; in which relativerolling movement causes the display of information stored as above orbelow currently displayed information.
 4. A portable computercomprising: movement detection means responsive to movement of thecomputer to produce an electrical output signal representative of suchmovement; processing means responsive to the output of said movementdetection means to determine detected movement data defining a user'sintention; the processing means using said data to provide a moderesponse selected from a multiplicity of stored possible modes; andwherein the processing means is responsive to detected movement data todetermine a most likely orientation of a computer display means, theprocessing means causing the displayed information to be orientedaccordingly.
 5. A portable computer as in claim 4, in which a pluralityof switch means responsive to user action is included adjacent to thedisplay means, the respective function of each of the switch means beingoriented to match the orientation of displayed information.
 6. Aportable computer as in claim 4 further comprising a touch sensitivestatic potentiometer strip responsive to movement of a user's finger tosimulate movement of a potentiometer, the orientation of saidpotentiometer reflecting the orientation of the displayed information.7. A portable computer comprising: movement detection means responsiveto movement of the computer to produce an electrical output signalrepresentative of such movement; processing means responsive to theoutput of said movement detection means to determine detected movementdata defining a user's intention, the processing means using said datato provide a mode response selected from a multiplicity of storedpossible modes; and proximity detection means which provides signalsindicative of the proximity of a computer display screen to a user'sview, the processing means being further responsive to changes inrelative proximity to increase or decrease the density of displayedinformation.
 8. A portable computer comprising: movement detection meansresponsive to movement of the computer to produce an electrical outputsignal representative of such movement; a storage medium for storingdata defining a multiplicity of displayable pages each comprising of aplurality of lines; a display having a corresponding plurality of linesto enable one of the multiplicity of pages to be displayed; andprocessing means responsive to the output of said movement detectionmeans to determine detected movement data defining a user's intention;the processing means using said movement data to provide a mode responseselected from a multiplicity of stored possible modes, at least some ofwhich define selection for display of a further one of the pages fromthe multiplicity of pages, the further one of the pages being adjacentto a previously selected page being currently displayed; radiotransceiver means, the processing means being responsive to detectedmovement data which identifies another device to cause the transmissionof coded signals including a message for display.
 9. A portable computeras in claim 8 in which the processing means is responsive to receivedencoded radio signals to activate a paging alert.
 10. A portablecomputer as in claim 9, in which the page alert comprises a tone.
 11. Aportable computer as in claim 9, in which the paging alert comprises anoperation of a vibrating means.
 12. A portable computer as in claim 8,in which the processing means causes the display of a message derivedfrom the information received.
 13. A portable computer comprising: acasing for housing other components of the portable computer, the casingbeing shaped to facilitate a user holding the portable computer as awriting stylus; and a display screen; wherein said casing includes aradiused triangular cross-section along a substantial portion of itslength and a flattened section incorporating the display screen, and anangular shaping between a forward holding area adapted to rest in theuser's fingers and rearward flattened area holding the display screenthe shaping being such as to provide a natural viewing angle of theincorporated display screen while the casing is held as a writingstylus.
 14. A portable computer as in claim 13, in which the shapingcauses the rearward screen area to be supported by the dorsal areas of auser's hand.
 15. A portable computer comprising: movement detectionmeans responsive to movement of the computer to produce an electricaloutput signal representative of such movement; a storage medium forstoring data defining a multiplicity of displayable pages eachcomprising of a plurality of lines; a display having a correspondingplurality of lines to enable one of the multiplicity of pages to bedisplayed; and processing means responsive to the output of saidmovement detection means to determine detected movement data defining auser's intention; the processing means using said movement data toprovide a mode response selected from a multiplicity of stored possiblemodes, at least some of which define selection for display of a furtherone of the pages from the multiplicity of pages being the further one ofthe pages being adjacent to a previously selected page being currentlydisplayed; wherein the processing means is responsive to detectedmovement data to determine a most likely orientation of the display, theprocessing means causing the displayed information to be orientedaccordingly.
 16. A portable computer comprising: movement detectionmeans responsive to movement of the computer to produce an electricaloutput signal representative of such movement; a storage medium forstoring data defining a multiplicity of displayable pages eachcomprising of a plurality of lines; a display having a correspondingplurality of lines to enable one of the multiplicity of pages to bedisplayed; and processing means responsive to the output of saidmovement detection means to determine detected movement data defining auser's intention; the processing means using said movement data toprovide a mode response selected from a multiplicity of stored possiblemodes, at least some of which define selection for display of a furtherone of the pages from the multiplicity of pages, the further one of thepages being adjacent to a previously selected page being currentlydisplayed; in which a plurality of switch means responsive to useraction is included adjacent to the display, the respective function ofeach of the switch means being oriented to match the orientation ofdisplayed information.
 17. A portable computer comprising: movementdetection means responsive to movement of the computer to produce anelectrical output signal representative of such movement; a storagemedium for storing data defining a multiplicity of displayable pageseach comprising of a plurality of lines; a display having acorresponding plurality of lines to enable one of the multiplicity ofpages to be displayed; processing means responsive to the output of saidmovement detection means to determine detected movement data defining auser's intention, the processing means using said movement data toprovide a mode response selected from a multiplicity of stored possiblemodes, at least some of which define selection for display of a furtherone of the pages from the multiplicity of pages, the further one of thepages being adjacent to a previously selected page being currentlydisplayed; and a touch sensitive static potentiometer strip responsiveto movement of a users finger to simulate movement of a potentiometer,the orientation of said potentiometer reflecting the orientation of thedisplayed information.
 18. A portable computer comprising: movementdetection means responsive to movement of the computer to produce anelectrical output signal representative of such movement; a storagemedium for storing data defining a multiplicity of displayable pageseach comprising of a plurality of lines; a display having acorresponding plurality of lines to enable one of the multiplicity ofpages to be displayed; and processing means responsive to the output ofsaid movement detection means to determine detected movement datadefining a user's intention; wherein detected movement data is used toeffect scrolling of displayed information such that portions of datadefining alphanumeric or graphic information outside a currentlydisplayed screen is selectable by the user, the scrolling of displayedinformation effectively displaying a part of an adjacent screen.
 19. Aportable computer as in claim 18, including a sound output device, theprocessing means being arranged to provide output of speech or othersound signals derived from stored data.
 20. A portable computer as inclaim 18, including radio transmission or infrared transmission means,the processing means being responsive to detected movement data tooutput to the transmission means signals representative of the detectedmovement.
 21. A portable computer as in claim 18, including radiotransmission or infrared transmission means, the processing means beingresponsive to detected movement data to output to the transmission meanssignals representative of alphanumeric characters.
 22. A portablecomputer as in claim 18, in which the processing means stores datadefining an authorised user's password, the processing means beinglocked in a secure mode until detected movement data corresponding tothe security data is received.
 23. A portable computer as in claim 18,further comprising a sound input device, the processing means beingresponsive to voice input signals from a user to derive alphanumericdata.
 24. A portable computer as in claim 23, further including a soundoutput device in combination with a radio transceiver whereby cellularor radio telephony networks may be used.
 25. A portable computer as inclaim 18 housed in a casing shaped to facilitate a user holding thecomputer as a writing stylus.
 26. A portable computer as in claim 25, inwhich the casing comprises a radiused triangular cross-section along asubstantial portion of its length.
 27. A portable computer as in claim26, in which the casing includes a flattened section incorporating adisplay screen.
 28. A portable computer comprising: movement detectionmeans responsive to movement of the computer to produce an electricaloutput signal representative of such movement; a storage medium forstoring data defining a multiplicity of displayable pages eachcomprising of a plurality of lines; a display having a correspondingplurality of lines to enable one of the multiplicity of pages to bedisplayed; and processing means responsive to the output of saidmovement detection means to determine detected movement data defining auser's intention; in which a relative lateral tilting movement causesthe display of information stored as to one or other side of currentlydisplayed information.
 29. A portable computer as in claim 28 housed ina casing shaped to facilitate a user holding the computer as a writingstylus.
 30. A portable computer as in claim 29, in which the casingcomprises a radiused triangular cross-section along a substantialportion of its length.
 31. A portable computer as in claim 30, in whichthe casing includes a flattened section incorporating a display screen.32. A portable computer comprising: movement detection means responsiveto movement of the computer to produce an electrical output signalrepresentative of such movement; a storage medium for storing datadefining a multiplicity of displayable pages each comprising of aplurality of lines; a display having a corresponding plurality of linesto enable one of the multiplicity of pages to be displayed; andprocessing means responsive to the output of said movement detectionmeans to determine detected movement data defining a user's intention;in which relative rolling movement causes the display of informationstored as above or below currently displayed information.
 33. A portablecomputer as in claim 32 housed in a casing shaped to facilitate a userholding the computer as a writing stylus.
 34. A portable computer as inclaim 33, in which the casing comprises a radiused triangularcross-section along a substantial portion of its length.
 35. A portablecomputer as in claim 34, in which the casing includes a flattenedsection incorporating a display screen.
 36. A portable computercomprising: movement detection means responsive to movement of thecomputer to produce an electrical output signal representative of suchmovement; a storage medium for storing data defining a multiplicity ofdisplayable pages each comprising of a plurality of lines; a displayhaving a corresponding plurality of lines to enable one of themultiplicity of pages to be displayed; and processing means responsiveto the output of said movement detection means to determine detectedmovement data defining a user's intention; wherein the processing meansis responsive to detected movement data to determine a most likelyorientation of the display, the processing means causing the displayedinformation to be oriented accordingly.
 37. A hand held cellulartelephone comprising: a case; the case being unitary and withoutcomprising a hinge; the case being sized and shaped to be held withinone hand of a user; the case also containing a cellular transceiver; thecase also containing a processor; a rechargeable battery also beinghoused within the case; a display that displays information, the displaydisposed on the case; the screen area of the display being of a sizesuch that it extends between the root of a thumb and an index finger ofa user and extending to the user's wrist; a detector that generates dataindicative of whether a user is looking at the display; the displaybeing powered by a rechargeable battery; and the processor beingconfigured to reduce power supplied by the rechargeable battery to thedisplay based on the data generated by the detector.
 38. The hand heldcellular telephone of claim 37, wherein the display comprises a touchscreen.
 39. The hand held cellular telephone of claim 37, wherein thehousing comprises a molded plastic case which is sealed to make the casewaterproof.
 40. The hand held cellular telephone of claim 37, furthercomprising a light emitting diode.
 41. The hand held cellular telephoneof claim 40, wherein the light emitting diode may emit light of morethan one color.
 42. The hand held cellular telephone of claim 40,wherein the light emitting diode emits a red color.
 43. The hand heldcellular telephone of claim 37, further comprising configuring the handheld cellular telephone to perform multiple functions selected from thegroup consisting of at least one of: reception and transmission ofemail; storage and display of large text documents; diary alarm andscheduling functions; storage and display of maps; and storing andsorting speech notes.
 44. The hand held cellular telephone of claim 43,wherein the at least one function of storage and display of large textmessages comprises the storage and display of photographs.
 45. The handheld cellular telephone of claim 43, wherein the at least one functionis storage and display of maps.
 46. The cellular telephone of claim 37,wherein the display comprises a liquid crystal display furthercomprising a backlight.
 47. The cellular telephone of claim 46, whereinthe processor is configured to reduce power to the liquid crystaldisplay by closing down the backlight of the display.